From 351d0ae98dfb734d9b4637771caf55652ab447a4 Mon Sep 17 00:00:00 2001 From: Daniel Chen <eggyrules@gmail.com> Date: Thu, 7 Nov 2019 14:56:17 +0000 Subject: [PATCH] Update Unit 2: Biology.md --- Grade 10/Science/SNC2DZ/Unit 2: Biology.md | 15 +++++++++++---- 1 file changed, 11 insertions(+), 4 deletions(-) diff --git a/Grade 10/Science/SNC2DZ/Unit 2: Biology.md b/Grade 10/Science/SNC2DZ/Unit 2: Biology.md index 3dacf5f..ae54afa 100644 --- a/Grade 10/Science/SNC2DZ/Unit 2: Biology.md +++ b/Grade 10/Science/SNC2DZ/Unit 2: Biology.md @@ -122,9 +122,13 @@ A person contains roughly 100 trillion cells 1. Centrioles and centrosomes 2. Lysosomes -### Centrioles and centrosomes +### Centrosomes - Made of same protein as `cytoskeleton` - - Create and manipulate spindle during mitosis in animal cells + - **Create and manipulate spindle* during mitosis in animal cells + - One centrosome is a bound pair of two `centrioles` + - Centrioles are present in a few types of plant cells + - Centrioles **create** spindle during mitosis in both plant and animal cells + - Centrioles do not manipulate spindle ### Lysosomes - Explained before. @@ -231,12 +235,15 @@ A person contains roughly 100 trillion cells - In **animal cells**: Cell membrane pulled inward by cytoskeleton - **"Pinches in"** along equator of cell, forming **"cleavage furrow"** - In **plant cells**: Golgi apparatus produces and sends vesicles to centre of plant cell **"cell plate"** to make new cell wall and membrane between daughter cells + ## Cell Specialization -- `Zygote`: A single-celled organism formed from the fertilization of an egg by a sperm cell +- `Zygote`: A single-celled organism formed from the fertilization of an egg by a sperm cell, is a totipotent stem cell - A cell's position in the `gastrula` (outer, middle, inner layer) will determine the fate of the cell, or its potiental. +- Chemical signals from other cells will also determine activated genes that lead to specialisation - (LOCATION LOCATION LOCAION!) +- Specialisation is determined by reading only certain genes ### Stem Cells - They are an **unspecialized** cell that has the potential to become one of several types of cells. -- After cell division, either both can become stem cells or one stays as a stem cell and the other becomes a specialized cell +- Can either divide to two stem cells or - \ No newline at end of file